In general, gas turbines are being subjected to more demanding operation. Higher temperatures, harsher environments, use in more diverse environments, and extended duration of use result in challenges for gas turbines and their components. Extending the useful life of such components and improving capability for repair of such components can decrease costs associated with the gas turbines and can increase the operational aspects of the gas turbines.
Known end covers on fuel nozzles in gas turbines have an insert brazed into the end cover. Generally, such inserts have four braze joints securing the inserts within the end cover. These braze joints are subject to failure, for example, resulting in leaking proximal to the braze joints. Such braze joints can also suffer from a drawback of requiring frequent repair. Such repairs can be complex and expensive. In addition, the ability to perform such repairs may be limited.
Repair of known end covers can result in further leaking that is not capable of being repaired. For example, when an insert is removed for repair, the braze joints are severed. Repeated severing of the braze joints can result in undesirable operational concerns, such as leaking, that is not capable of being adequately repaired. Known end covers suffer from a drawback of being limited to three such iterations of repeated repair.
Other techniques for securing fuel nozzle inserts within fuel nozzle end covers have been unavailable. In particular, the complex geometry of the insert and the difficulty reaching certain portions within the fuel nozzle when the insert is positioned within the end cover has prevented use of techniques other than brazing.
A fuel nozzle and a process of fabricating a fuel nozzle that do not suffer from one or more of the above drawbacks would be desirable in the art.